P.X. Tran, P. Wang
National Energy Technology Lab,
Keywords: microchannel, laser motion, nanofluids
Summary:Laser-Induced Motion of a Nanofluid in a Micro-channel Tran X. Phuoc, Mehrdad Massoudi and Ping Wang National Energy Technology Laboratory, U. S. Department of Energy, P. O. Box 10940 Pittsburgh, PA 15236 * Corresponding author: email@example.com Summary In this paper we report our theoretical study on the use of a laser beam to manipulate and control the flow of nanofluids in a micro-channel. We calculate the velocity induced by a laser beam for TiO2, Fe2O3, Al2O3 MgO, and SiO2 nanoparticles with water as the base fluid. The particle diameter is 50 nm and the laser beam is a 4 W CW beam of 6 mm diameter and 532 nm wavelength. The results indicate that, as the particle moves, a significant volume of the surrounding water (up to about 8 particle diameters away from the particle surface) is disturbed and dragged along with the moving particle. The results also show the effect of the particle refractive index on the particle velocity and the induced volume flow rate. The velocity and the volume flowrate induced by TiO2 nanoparticle, (refractive index n = 2.82), are about 0.552 mm/s and 9.86 fL, respectively, while those by SiO2 (n = 1.46) are only about 7.569 μm/s and 0.135, respectively. Thus, using a laser beam to manipulate the flow of a nanofluid in a microchannel is possible and it has many advantages over other conventional methods. Such advantages are deduced from the fact that there are no moving parts, no external pumps are required and the channels do not need to electronically reconfigure. Additionally, using a fiberoptic cable, the laser beam can be distributed and delivered to multiple micro-channels that can be operated either sequentially or simultaneously. The location of the beam waist can be varied, thus, the flow can be initiated at different location throughout the micro-channels.